1. Field of the Invention
The present invention relates to protection means for preventing unauthorized entry through doors.
2. Description of the Prior Art
Heretofore, various means have been developed for preventing or hindering access through a door or the like. See, for example, Zell, U.S. Pat. No. 79,047; Whitney, U.S. Pat. No. 158,876; Kern, U.S. Pat. No. 438,626; Dengler, U.S. Pat. No. 817,962; Bumpass, U.S. Pat. No. 1,413,573; Gettell, U.S. Pat. No. 1,535,770; Irwin, U.S. Pat. No. 1,792,537; Drenthe, U.S. Pat. No. 1,984,012; Sullivan, U.S. Pat. No. 2,018,098; Davis, U.S. Pat. No. 2,203,675; Lopina, U.S. Pat. No. 3,391,512; Arai, U.S. Pat. No. 3,863,762; and Dumortier, U.S. Pat. No. 4,175,781. None of the above patents disclose or suggest the present invention.